20.1 Surgical Techniques for Peroneal Tendons Subluxation
20.1.1 Introduction
Peroneal tendons dislocation is an uncommon sports-related injury. The first case was described by Monteggia in 1803 in a ballet dancer.1 The injury is frequently associated with sports with cutting maneuvers such as judo, gymnastics, soccer, rugby, basketball, ice skating, skiing, water skiing, and mountaineering.2 No specific age range is associated with the condition, but it clearly appears from the reported series that there is a relation-ship between dislocation of peroneal tendons and sport active people and road accidents.
Acute traumatic subluxation of the peroneal tendons is uncommon.3 Acute injuries to the superior peroneal retinaculum can be initially managed conservatively with immobilization in a non-weight-bearing cast; this has a success rate of approximately 50%,3,4 with pre-adolescent patients showing high rates of resolution after conservative management.5
In chronic subluxation, patients often report previ-ous ankle injuries that, in some cases, may have been misdiagnosed as a sprain. An unstable ankle that gives way or is associated with a popping or snapping sensation is another common complaint. Chronic subluxation of the peroneal tendons may be traumatic or habitual and voluntary. In the latter case, congenital
deficiency of the superior peroneal retinaculum (SPR) and a shallow fibular groove may play a role.6 In trau-matic chronic subluxation, there is little to be gained with conservative management, and surgical man-agement is generally advocated.4,6-12 Often the clini-cal diagnosis can be difficult, and some authors report a 60% diagnostic capability at first clinical evaluation.13
20.1.2 Anatomy
The peroneal muscles lie in the lateral compartment of the leg. They are innervated by the superficial peroneal nerve and supplied by the posterior peroneal artery and branches of the medial tarsal artery. The peroneus longus muscle originates from the head and upper two-thirds of the peroneal surface of the fibula, and from the intermuscular septa. In 20% of Caucasians, a sesamoid bone, the os peroneum, can be observed close to the calcaneocuboid joint. The peroneus brevis muscle originates from the lower two-thirds of the fibula in front of that of the peroneus longus. The two peroneal tendons enter together in a common syn-ovial sheath 4 cm above of the lateral malleolus, going through a fibro-osseous tunnel, the retromalleolar groove. The peroneus longus tendon lies posterior and lateral to the peroneus brevis tendon.
The peroneus tertius muscle, normally absent in 10.5% of dissected limbs, arises from the distal third of the anterior aspect of the fibula. The muscle belly, usually not separated from the extensor digitorum longus muscle, ends proximal to the inferior extensor retinaculum.14 This anatomical variant can rarely cause antero-lateral pain and snapping ankle.15
Peroneal Tendinopathy
Francesco Oliva, Amol Saxena, Nicholas Antonio Ferran, and Nicola Maffulli
20
A. Saxena ( ) PAFMG-Palo Alto Division, Department of Sports Medicine, Clark Bldg., 3rd Flr, 795 El Camino Real, Palo Alto, CA 94301, USAe-mail: [email protected]
194 F. Oliva et al.
Another anatomical variant of the peroneal tendons is the rare peroneus quartus, which, with a number of different attachments, is present in 6.6% of the dis-sected legs.16 This tendon is as important as the per-oneus tertius in the differential diagnosis with peroneal tendons subluxation and posterolateral ankle pain.
The retrofibular (also called retromalleolar) groove is formed not by the concavity of the fibula itself, but by a relatively pronounced ridge of collagenous soft tissue blended with the periosteum that extends along the posterolateral lip of the distal fibula.17,18 The other component of the retrofibular groove is the SPR posterolaterally, a fibrous band that originates from the distal lateral surface of fibula. The SPR is extremely variable in width, thickness, and inser-tional patterns. It normally has two bands: The supe-rior band inserts on the Achilles tendon19; the inferior band inserts on the peroneal tubercle on the lateral surface of calcaneus.20
The peroneus longus passes between the cuboid groove and the long plantar ligament, and inserts onto the plantar surface of 1st metatarsal and the lateral face of medial cuneiform. The sural nerve lies in proximity of the peroneal groove. The sural nerve descends between the medial and lateral heads of the gastrocnemius, pierces of deep fascia proximally in the leg, and is joined by a sural communicating branch of the common peroneal nerve. It descends lateral to the Achilles tendon, near the small saphenous vein, to the region between the lateral malleo-lus and the calcaneus. It supplies the posterior and lateral skin of the distal third of the leg, proceeding distal to the lateral malleolus along the lateral side of the foot and little toe. It should be preserved at surgery.
The peroneal tendons receive their vascular supply from separate vincula that arise from the posterior per-oneal artery and from the medial tarsal artery.21 There are three distinct avascular zones: one in the peroneus brevis tendon when it curves around the lateral malleo-lus, and two in the peroneus longus.22 The first avascu-lar zone in the peroneus longus lies at the curve around the lateral malleolus, and the second occurs where the tendon curves around the cuboid.22
The peroneus brevis abducts and everts the foot, and flexes the foot plantarly. The peroneus longus plays the same functions of the peroneus brevis, but it is an important stabilizer of the medial column of the foot during stance. Together, they are dynamic stabi-lizers of the lateral ankle complex. Their antagonists are the flexor digitorum longus, flexor hallucis longus, and posterior and anterior tibialis.
20.1.3 Physiopathology
An acute peroneal tendons subluxation may occur when the tendons dislocate from the retrofibular groove during tendon loading. The most common mechanism is a sudden, reflexive contraction of the peroneal muscles during acute inversion of the foot with the ankle dorsiflexed, or during forced dorsiflex-ion of the everted foot.20 Basset and Speer analyzed the links between the position of the foot and the type of disorders as a result of inversion ankle injuries. Ankle inversion and plantar flexion less than 15° may produce an injury of the SPR. At a plantar flexion angle greater than 25°, the peroneal tendons are protected from injury.23
The SPR is the primary restraint of the peroneal tendons: Its integrity is fundamental to avoid a per-oneal tendon subluxation.24 Disruption of the SPR occurs infrequently.25 Damages of the SPR are associ-ated with lateral ankle instability and inadequate con-cavity or depth of the retromalleolar groove.26 Laxity of the SPR can result from a calcaneovalgus foot in neuromuscular diseases. Also, the rare congenital absence of the SPR must be considered as contribu-tor to the mechanism of dislocation.27-29
Acute rupture of the SPR with potential sublux-ation of the peroneal tendons may cause longitudinal tears in the peroneus brevis tendon.22 In the anatomi-cal area where the peroneus brevis tendon passes through the fibular groove, the tendon is nearly avas-cular.22 In cadaveric studies, disruption of the lateral collateral ankle ligaments places considerable strain on the SPR: this explains why the two conditions commonly coexist.26
Still poorly studied are non-traumatic subluxations of peroneal tendons, which can be caused by congen-ital or acquired pathological conditions. Hence, sev-eral congenital anatomical abnormalities, as a convex, flat or shallow, or, in rare cases, even absent retrofibu-lar groove, may be present.25,29 The absence of the SPR may also be congenital.30 A bifid peroneus bre-vis has also been reported as a cause of subluxation.31 A paralytic calcaneovalgus ankle is often associated with laxity of the retinaculum.32 Congenital disloca-tion of the peroneal tendons may be associated with a calcaneovalgus foot type.29 Acquired peroneal tendon subluxation is described in patients with neuromus-cular diseases such as cerebral palsy,3 and can also occur when the posterior surface of the lateral fibula is deformed as a consequence of osteochondritis.33
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20.1.4 Classifications
Peroneal tendons subluxation is due mostly to a dam-age of the SPR. Eckert and Davis in 1976 distinguished three grades of acute tears. In grade 1, the retinaculum is separated from the collagenous lip and lateral mal-leolus. In grade 2, the collagenous lip is elevated with the retinaculum. In grade 3, a thin sliver of bone, visi-ble on radiographs, is avulsed with the collagenous lip and the retinaculum.25 Ogden in 1987 added a fourth grade, describing it as the SPR torn away from its pos-terior attachment on the calcaneus.34 Clinical determi-nation of injury grade is not possible, except for grade 3 injuries, which can be diagnosed on radiographs. Previously, some authors have described an intrasheath peroneal subluxation,35,36 but only recently Raikin and colleagues37 proposed as a subgroup of peroneal sub-luxation an intrasheath subluxation. In this instance, the peroneal tendons switch their relative positions (the longus tendon comes to lie deep and medial to the brevis tendon) within the peroneal groove. An associ-ated tear of the peroneous brevis is described without any lesion of the superior retinaculum. The clinical signs of intrasheath subluxation are very similar to the grade 1 of Eckert and Davis classification, but ultrasonography can help to diagnose these variants. Realistically, it is hard to believe that the SPR remains intact during a switch of the positions of the peroneal tendons. Hence, probably even intrasheath peroneal dislocations should be classified as a grade I injury according to Eckert and Davis (Fig. 20.1).
20.1.5 Surgical Techniques
Many surgical techniques limited only to case series have been described but only Level IV/Grade C evi-dence has been produced. No randomized studies have been conducted to determine which procedure is the most successful. (Table 20.1)38-56 Generally, five cate-gories of surgical repair are listed: (1) Anatomic reat-tachment of the retinaculum; (2) Reinforcement of the superior peroneal retinaculum with local tissue trans-fers; (3) Rerouting the peroneal tendons behind the calcaneofibular ligament; (4) Bone block procedures; (5) Groove-deepening procedures.
20.1.5.1 Anatomic Reattachment of SPRThe aim of anatomic reattachment of the SPR is the restoration of the primary restraint of the peroneal ten-dons. Reattachment with sutures brought through drill holes in the distal fibula has been described by several authors.8,25,38-40,47,48 Alternatively, Beck6 brought the retinaculum through a slip produced in the distal fibula and fixed this with a screw, reporting on nine patients without complication. Eighteen of 21 patients treated with the “Singapore operation” at 9 years had excel-lent results. Three patients experienced postoperative pain and neuromas, but no recurrence was noted.50 Karlsson and colleagues reported 13 patients with good to excellent results associating a groove deepen-ing in conjunction with reattachment of the SPR if the posterior surface of the fibula was flat or convex.48 Orthner et al. obtained excellent results for peroneal
a b
Fig. 20.1 (a) Pre-op X-ray showing avulsed peroneal retinacu-lum. (b) MRI showing torn peroneal retinaculum. (c) Diagram of the classification of peroneal retinaculum tears. PLT, peroneus
longus tendon; PBT, peroneus brevis tendon; SPR, superior peroneal retinaculum
196 F. Oliva et al.
tendons subluxation suturing side by side the SPR in acute lesions.43 Adachi et al. proposed retinaculoplasty, opening the false pouch through one incision, and suturing the SPR to the fibula while tensioning it. In this study, the authors reported that 15 of the 18 patients involved in sports activities returned to their previous activities without reducing their activity levels.54 Recently, an endoscopic technique for the anatomical repair of the SPR has been described.57 Anatomic reat-tachment of superior retinaculum seems to be the pre-ferred technique in patients with acute subluxation of peroneal tendons.
20.1.5.2 Reinforcement of SPR with Soft Tissue
Several authors have described procedures to aug-ment or reinforce an attenuated SPR with soft tissue transfer. Ellis-Jones58 first described restraining the peroneal tendons with a strip of Achilles tendon anchored through a drill hole in the fibula. No recur-rences were noted in a long-term follow-up of 15 patients who underwent the Ellis-Jones repair.4 Thomas et al.45 described a modification to this pro-cedure that allowed the use of a smaller strip of Achilles tendon, reducing the risk of weakening the
G1a G1b G1c
PLT
PBT
PLT
PBTPBTPBT
PLT
G2 G3 G4
Calcaneus
PBT
PLTPBT
PLT
PBT
PLT
Normal
Collagenous lip
SPR
PBT
PLT
Fibula
cFig.20.1 (continued)
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Achilles tendon. Use of the tendon of peroneus brevis,39,59,60 plantaris61,62 and peroneus quartus63 have been described for the same purpose. Zoellner and Clancy12 and Gould9 used periosteal flaps to restrain the peroneal tendons in a deepened peroneal groove with satisfactory results. In patients treated with a periosteal flap from the retrofibular groove on its own or together with groove deepening, no postoperative complications were noted.64
20.1.5.3 Rerouting the Peroneal Tendons Behind the Calcaneofibular Ligament
This surgical technique does not address the issue of restoration of the anatomy of the SPR, but uses the calcaneofibular ligament as the natural alterna-tive restraint. Platzgummer65 and later Steinbock et al.46 divided the calcaneofibular ligament, trans-posed the tendons behind it, and sutured the calca-neofibular ligament back together. The 13 patients operated with this technique showed good or excellent results, with no evidence of recurrence or
instability. Sarmiento and Wolf divided the peroneal tendons and re-sutured them after rerouting them behind the calcaneofibular ligament66; 11 patients showed no evidence of recurrence or instability at follow-up, although two patients suffered a sural nerve injury. Martens et al. used the same technique of Sarmiento with excellent results at 30-month follow-up in 11 patients.41 Both methods may poten-tially weaken the relevant structures. To preserve the integrity of the calcaneofibular ligament, a bone block of the ligamentous insertion on the fibula67 or the calcaneus40 can be mobilized, the tendons are trans-posed, and the bone block is reattached with a screw. Pozzo and Jackson11 reported no complication and return to full level of activity in a case report. Poll and Duijfjes40 reported ten patients with no recur-rence or instability. Ferroudji et al. reported their experience with 19 patients, with excellent results in 17 patients. Sports activities were resumed after an average of 3.3 months.68 This surgical technique should be preferred in patients with chronic luxation of the peroneal tendons in whom the SPR is absent.
Table 20.1 Studies and surgical techniques for the management of peroneal tendons subluxation
Authors Year Level of evidence Number of cases Procedures
Eckert and Davis25 1976 IV 73 Anatomical reattachment of SPRMarti38 1977 IV 12 Modified KellyZoellner and Clancy12 1979 IV 9 Groove deepeningEscalas et al.4 1980 IV 28 Jones procedureArrowsmith et al.39 1983 IV 6 Anatomical reattachment of SPR plus
groove deepeningPoll and Duijfjes40 1984 IV 10 Rerouting tendon under CFLMartens et al.41 1986 IV 11 Rerouting tendon under CFLMicheli et al.42 1989 IV 12 Modified kellyOrthner et al.43 1989 IV 23 Anatomical reattachment plus screwWirth44 1990 IV 15 Modified Viernstein and KellyThomas et al.45 1992 IV 31 Modified Ellis-JonesSteinböck et al.46 1994 IV 13 Rerouting tendon under CFLMason and Henderson47 1996 IV 11 Anatomical reattachment of SPRKarlsson et al.48 1996 IV 15 Soft tissue reconstruction of superior
retinaculumKollias and Ferkel49 1997 IV 12 Groove deepeningHui et al.50 1998 IV 21 Anatomical reattachment of SPRMendicino et al.51 2001 IV ? Groove deepeningShawen et al.52 2004 IV 20 Groove deepeningPorter D, McCarrol J et al.53 2005 IV 13 Groove deepeningAdachi et al.54 2006 IV 20 Anatomical reattachment of SPRMaffulli et al.55 2006 IV 14 Anatomical reattachment of SPROgawa et al.56 2007 IV 15 Groove deepening
Studies which reported less than five patients are not listed
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20.1.5.4 Bone Block ProcedureThese surgical procedures were developed to deepen the retrofibular groove using a bone graft as a physical restraint to the peroneal tendons. In 1920, Kelly67 described a bone block procedure using screw fixation and later designed a wedge-shaped graft that avoided the use of screws near the ankle joint. Watson-Jones and DuVries69,70 modified Kelly’s technique. Watson-Jones69 used an osteoperiosteal flap anchored by a soft tissue pedicle, and secured it posteriorly with sutures. DuVries70 anchored a posteriorly displaced wedge with a screw. Other authors reported on patients with chronic subluxation operated with a modified Kelly technique with no recurrence.38,44 In 1989, Micheli and colleagues42 treated 12 patients with an inferiorly dis-placed fibula bone graft fixed with screws; one patient suffered a traumatic fracture of the graft, and two required exploration for pain; there were no recur-rences of the subluxation. Adhesion of the peroneal tendons to the fresh bone wound, fractures of bone grafts, and the need for metalwork are major disad-vantages of bone block procedures.6 This surgical technique seems to be the more exposed to intraop-erative and postoperative complications, and should be reserved for selected cases.
20.1.5.5 Groove DeepeningPatients presenting with a flat or convex retrofibular sulcus could be managed with this surgical technique. Zoellner and Clancy12 elevated an osteoperiosteal flap on the posterior aspect of the distal fibula, and removed cancellous bone with a gouge. The flap was then reduced into the deepened sulcus, and the ten-dons replaced into this. Their nine patients had excel-lent results with no recurrence or instability. Hutchinson and Gustafson described a similar method in combina-tion with SPR reattachment. Of 20 patients, three had poor results with recurrence of the subluxation, and one of these developed reflex sympathetic dystrophy.71 Gould9 reported a single patient in whom groove deep-ening was incorporated with restraint of the peroneal tendons by reflection of elevated osteoperiosteal flap. Recently, Ogawa et al. used an indirect fibular groove–deepening technique.56 Mendicino and colleagues51 employed intramedullary drilling and cortical impac-tion to achieve groove deepening. Porter et al. pro-posed groove deepening associated with an accelerated rehabilitation program. Eight of 13 patients returned to pre-injury sports participation.53 The depth of the retrofibular sulcus was previously thought to play an
important role in restraining the peroneal tendons.49,52 Recently, however, the need for groove deepening has been questioned. Anatomic studies demonstrate the incidence of a flat or convex sulcus as high as 18%,72 28%,58 and 30%.73 The low incidence of peroneal ten-don subluxation would suggest that the morphology of the groove is not a predisposing factor to sublux-ation.72 Histologic studies demonstrating that the peroneal groove is defined by the fibrocartilagenous periosteal cushion and not by the bony sulcus add weight to this argument.
20.1.6 Preferred Surgical Technique
Under general or spinal anesthetic, the patient is placed supine on the operating table with a sandbag under the buttock of the operative side to internally rotate the affected leg. A tourniquet is applied to the thigh, the leg exsanguinated, and the cuff inflated to 250 mmHg. A 5-cm longitudinal incision is made along the course of the peroneal tendons. The incision starts posterior to the tip of the lateral malleolus and progressed proximally, staying well anterior to the sural nerve. The incision is deepened to the peroneal tendon sheath, which is incised longitudinally 3 mm posterior to the posterior border of the fibula. Normally, the SPR itself is thin and deficient, and it was detached from its posterior attachment on the calcaneus in our case series.55 The peroneal tendons are identified by blunt dissection and protected. Attrition lesions and longitudinal tears of peroneal tendons when found are treated with a very gentle débridement or suturing with absorbable sutures.74-76 After that, we expose the lateral aspect of the lateral malleolus, and the “pouch” formed between the bony surface of the lateral malleolus and the superior peroneal retinaculum, where the tendons subluxate, becomes visible. The SPR does not heal back to its normal attachment on the posterolat-eral aspect of the fibula but in an elongated fashion more anteriorly on the lateral aspect of the fibula, creating a pouch on the lateral fibula into which the tendons can subluxate. The bony surface of the lateral malleolus is roughened with a periosteal elevator to produce a bleed-ing surface, and three or four an chors (Mitek GII, Ethicon Ltd, Edinburgh, Scotland) with 2/0 absorbable sutures (Vicryl, polyglactin 910 braided absorbable suture, Ethicon) are inserted along the posterior border of the lower fibula (Fig. 20.2). After manual testing that the anchors cannot be dislodged, the SPR is recon-structed in a “vest over pants” fashion,74 making sure
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that the pouch between the bony surface of the lateral malleolus and the SPR is totally obliterated. The ankle is kept in eversion and slight dorsiflexion so that the per-oneal tendons were in the “worst possible position.” The strength of the repair is tested moving the ankle through the whole range of motion. The wound is
closed in layers with 2/0 Vicryl for the subcutaneous fat, un-dyed 3/0 Vicryl for subcuticular, and Steri-Strips for the skin (3M, Loughborough, United Kingdom). Dressing swabs, dressing, and crepe ban-dage are applied. A below-the-knee walking cast is applied with the ankle in neutral and slight eversion. Weight bearing is allowed from the day after the oper-ation, and the cast is removed 4 weeks after the proce-dure, when rehabilitation is started. Gradual return to activities and to sport is allowed during the course of 3–4 months from the procedure.55,76
20.1.7 Postoperative Care
Patients are discharged the day after surgery, after hav-ing been taught to use crutches by an orthopedic phys-iotherapist. No thrombo-prophylaxis is used. Patients are allowed to bear weight on the operated leg as toler-ated, but are told to keep the leg elevated as much as possible for the first 2 postoperative weeks. Patients are seen on an outpatient basis at the second postopera-tive week, and the cast is removed 4 weeks from the operation. Patients then mobilize the ankle with phys-iotherapy guidance. They are allowed to partially weight-bear, and commenced gradual stretching and strengthening exercises over 8–10 weeks after sur-gery. Cycling and swimming are started 2 weeks after removal of the cast. Patients are allowed to return to their sport on the fifth postoperative month.55,75,76
20.2 Surgical Techniques for Peroneal Tendon Tears
20.2.1 Introduction
Peroneal tendon tears were thought to be uncommon and a relatively new entity when reported by Evans in 1966. Peroneal tendon tears were seldom described until the early 1990s, when numerous case reports and moder-ately sized case series were published.23,77-89 Peroneal tendon tears are thought to occur from both acute trauma and chronic instability, with and without subluxation. Peroneal retinaculum insufficiency is described in the preceding section. Chronic retinaculum insufficiency has been associated with peroneal tendon tears.80-82,90,91 As with peroneal retinaculum pathology, tendon tears can often be difficult to recognize immediately. Diagnostic tests and clinical exam are paramount.
a
b
c
Fig. 20.2 Anatomical reattachment of the superior retinaculum with anchors. (a) Diagram and (b) X-ray of anchor placement. (c) Intraoperative view of suture placement for retinaculum repair
200 F. Oliva et al.
Sobel and Mizel describe the proximal injuries as “Zone I” and the distal injuries associated with the Os Peroneum as “Zone II.” Zone I injuries generally involve tears and dislocations of the tendon of peroneus brevis, while Zone II injuries involve Peroneus Longus pathology often with an Os Peroneum. They coined this condition POPS, Painful Os Peroneum Syndrome.81 Surgical treatment for both regions is often effective; the current treatment rec-ommendations are based on Level IV & V Evidence.80
20.2.2 Anatomy
Much of the pertinent anatomy has been described in the previous section. In addition, the incidence of the Os Peroneum and its association with lateral foot pain should be considered.79,81 The Os Peroneum is present in 4–26% of individuals, depending on race and eth-nicity.79,92-94 A low-lying muscle from Peroneus Brevis or an anomalous Peroneus Quartus has also been associated with peroneal tendon tears (Fig. 20.3).16,95,96 Peroneal tubercle hypertrophy has also been noted with peroneal tendon tears.78-81,89
20.2.3 Clinical Findings
Patients with peroneal tendon tears complain of lat-eral ankle and foot pain. Acute onset of pain can occur with inversion injuries. Patients may state they felt a “pop” and have ankle weakness. Ankle instability was noted as early as 1979 with peroneal tears.97 Clinically,
patients may have noticeable pain with active resis-tance to the Peronei, and with single-legged weight bearing. Proprioception is altered. Swelling is often present along the peroneal tendons. Cavo-varus foot structure may be present causing a supinated foot structure, thereby putting more strain on the Peroneals. A Coleman block test should be performed to evaluate for a rigidly plantarflexed first ray causing hindfoot varus, versus a calcaneus varus (Fig. 20.4).80 Weight-bearing plain radiographs should identify ankle varus, degenerative arthritis, accessory ossicles, and exos-toses (Fig. 20.5). An Os Peroneum is often present within the Peroneus Longus tendon in either a bony or cartilaginous form. A proximally migrated Os Peroneum indicates rupture of the Peroneus Longus (Fig. 20.6).80-82,86,88,89,94 Other bony structures can be associated with peroneal tendinopathy. A hypertro-phied peroneal tubercle on the lateral calcaneus can often be associated with fraying and even laceration of the adjacent tendons, which is best visualized on MRI (Fig. 20.7).80-82,86 Subluxation of the Peronei from posterior to the fibula may result in tearing of the Peroneus Brevis in particular, more commonly in older patients (Fig. 20.8). This may be due to long-standing insufficiency.80,98 Inspection of shoe gear, inserts, and orthoses should also be performed. History of inflammatory arthritis such as rheumatoid arthritis, Gout and Reiter’s syndrome, and subsequent testing when indicated should be considered.99
Radiographic tests for peroneal tendinopathy also include tenograms and MRI examinations. Tenograms are useful for diagnosing stenosing tenosynovitis
(Fig. 20.9). MRI can also indentify this, particularly since fluid is often evident in pathological states of tendons.27,90 Ultrasound may be used as it shows fluid within the tendon sheath and has high specificity for
dislocations and tears, but osteochondral and transchon-dral defects and accessory ossicles may not be seen with ultrasound.37,80 Fluid in the peroneal sheath may be indicative of a longitudinal tear, particularly with MRI (Fig. 20.10).80,86,88,90 MRI has a fairly high sensitivity and specificity rate, and has become the “gold standard,” though false-positives occur very commonly.80,86,90 The fact that many patients have asymptomatic tears noted on MRI exams points to the critical importance of the clinical exam.
a
b
c
Fig. 20.4 (a) Patient with right-sided peroneus longus tear, with previous repair on left. Note plantarflexed 1st metatarsal. (b) Coleman block test showing varus rearfoot when forefoot is on the ground. (c) With forefoot suspended off the ground, the rear-foot moves to neutral. This demonstrates that the patient’s rearfoot varus deformity is due to the plantarflexed 1st metatarsal
Fig. 20.5 Prominent peroneal tubercle
Fig. 20.6 Proximally migrated os peroneum indicating per-oneus longus rupture
202 F. Oliva et al.
To conclude a patient may have a peroneal tendon tear when suggested on MRI, and it is important in this instance to document peroneal weakness and pain. A diagnostic injection within the peroneal sheath (from proximal to the retinaculum with approximately 2 mL of local anesthetic) providing relief can confirm the diagnosis, and is recommended in less clear-cut cases.81 Care should be taken not to anesthetize the local nerves and infiltrate into the ankle or subtalar joint, which can give false relief of symptoms from injecting the wrong structures. Generally, peroneal tenosynovitis without tendon tear responds to nonsurgical treatment. (In fact, the local anesthestic injection, if performed, can produce a volume adhesiotomy and further relieve symptoms.) Typical nonsurgical treatment of peroneal tendinopathy includes bracing, inserts including custom orthoses and/or shoes with lateral (valgus) wedging, physical Fig. 20.7 MRI showing hypertrophic peroneal tubercle causing
therapy and immobilization in a below-knee boot or cast, though the long-term results of this can be unsat-isfactory. If patients report worsening of symptoms with physical therapy, it is likely due to a peroneal ten-don tear becoming aggravated with increased activity. At this point, one should consider surgical interven-tion. Results of surgical treatment of peroneal tendon tears have been well-documented in case series with good success. Many authors report significant improve-ment of patients’ activity levels and functional scores post-surgery even in the long-term.13,27,80,82-87,89,91,98,99
20.2.4 Surgical Technique
Surgical treatment typically involves repair of the torn tendon(s). General anesthesia is typically pre-ferred with a pneumatic thigh tourniquet. Spinal or regional anesthesia may be used. The patient is gen-erally placed in the lateral position on a “bean bag,” unless other procedures such as ankle arthroscopy need to be performed. During the surgical portion of the tendon repair, the bean bag is inflated to help lateralize the patient if adequate internal rotation of the lower limb is available. Otherwise, the patient is re-positioned lateral intraoperatively, and re-prepping and draping is performed. It is helpful to mark the proposed lateral incision sites prior to distending the ankle joint with arthroscopy, if being performed prior to tendon repair.
A lateral incision is typically made along the course of the peronei tendons, in the region of the patient’s pain and pathology. The incision may be extended proximally if a retinaculum repair or a more proximal
rupture needs to be addressed. The distal portion of the incision can be directed more dorsally for concomitant ankle stabilization. The common peroneal sheath is incised, the tendons inspected, together with the adja-cent bony structures (Fig. 20.11). The tendons can be manipulated with moistened umbilical tape. When an Os Peroneum is excised, the distal and proximal aspects of the Peroneus Longus tendon are tenodesed to the Peroneus Brevis with 2–0 or 3–0 monofilament
Fig. 20.9 Tenogram of stenosing tenosynovitis
a
b
Fig. 20.10 Fluid in peroneal sheath on MRI with torn peroneals frontal (a) and axial (b) views
204 F. Oliva et al.
suture. In North America, nonabsorbable sutures are more commonly used, while in Europe, absorbable sutures are preferred.75,76,83-89 In patients with chroni-cally degenerated and frayed tendons, excision of the
abnormal tendon is performed. Delayed primary repair is commonly performed by tubularizing the torn ten-don with nonabsorbable monofilament suture, though other materials have been utilized. (Fig. 20.12) If there is a large gap after débridement of nonviable tissue, the tendon is tenodesed to the adjacent tendon. Some authors recommend tenodesis when greater than 50% of the tendon girth or 2 cm of the length is damaged.80,82,85,86 Tendon “substitutes” being utilized for tendon repair have been promoted, but no long-term studies exist to date. Often, in chronic cases when both tendons are torn, the Peroneus Longus has retracted proximally, and the distal aspect of the Peroneus Brevis is intact. In such cases, the tendon of peroneus Longus is tenodesed to the base of the 5th metatarsal to maintain eversion of the foot.81,86 The surgical wound is closed in layers.
If both tendons are severely damaged and not reconstructable, a free tendon graft may be used, such as doubled Plantaris tendon or a transfer of either the Flexor Hallucis or Digitorum Longus can be per-formed. An interim procedure of inserting a Hunter’s Rod as a temporary conduit has been described prior to delayed repair.80,91,100 A second procedure involv-ing tendon transfer for peroneal reconstruction is performed 3 months later.27,100
Surgically, other structural issues may need address-ing. Exostoses from the peroneal tubercle or distal fibula should be reduced.80,81,86 Bone wax can be applied. The surgeon should be prepared in older patients to apply supplemental bone graft/substitute when the peroneal tubercle is resected as often the
a
b
c
Fig. 20.11 (a) Peroneal sheath opened showing torn peroneus longus. (b) Peroneal sheath opened showing torn peroneus brevis. Note exostoses adjacent to tear (c)
Fig. 20.12 Repaired tendon
20520 Peroneal Tendinopathy
underlying calcaneus is cystic, particularly in females. Subluxations are surgically corrected with ligament repair, accessory muscle resection, and groove deepen-ing if needed, as described in the section above. Severe rearfoot varus deformity (>10°) generally should be addressed at the time of surgery, though, in highly ath-letic patients, this may be deferred.27,86 For calcaneal varus deformity, a combined lateral displacement and varus reducing osteotomy is performed with either plate or screw fixation (Fig. 20.13). With patients that have a rigidly plantarflexed 1st metatarsal, an osteot-omy of the base is performed to elevate it to the level of the 2nd metatarsal. Care should be taken to avoid creating a transfer lesion to the 2nd metatarsal, but this
is essentially unavoidable with a short 1st metatarsal. Consideration of prophylactic shortening of an elon-gated 2nd metatarsal should be done if elevating a short plantarflexed 1st metatarsal. Plate or screw fixa-tion is also used on the 1st metatarsal (Fig. 20.14). Other surgical considerations for severe instability are subtalar arthrodesis (for absent Peroneus Brevis) or calcaneal-cuboid arthrodesis (for absent Peroneus Longus). 27,81 Postoperative complications from per-oneal tendon repair can include continued symptoms
a
b
Fig. 20.13 Lateral displacement calcaneal osteotomy in a patient with severe calcaneal varus and both peroneal tendons ruptured, oblique (a) and lateral (b) X-rays
a
b
Fig. 20.14 Elevating 1st metatarsal osteotomy in a patient with torn peroneus brevis and plantarflexed 1st metatarsal lateral (a) and AP (b) X-rays
206 F. Oliva et al.
with activity limitations, re-rupture (particularly if structural deformity is not addressed), and neurovascu-lar compromise.27,80,85,86
20.2.5 Postoperative Care
Postoperatively patients with peroneal tendon repair alone are kept non-weight bearing for 3 weeks, gener-ally with a below-knee cast or boot. Stationary biking with the heel on the pedal is permitted with a boot or cast once edema and pain subsides, and swimming is allowed after 4 weeks. Ankle range-of-motion exer-cises can be begun at 3 weeks. If a calcaneal or 1st metatarsal osteotomy is performed, patients are kept non-weight bearing for 4–6 weeks, depending on bony consolidation. Patients wear a below-knee cast boot for 6–10 weeks until pain-free (the longer time frame is used for patients with osteotomies). Physical therapy is initiated between 5 and 10 weeks. Return to regular activities including sports takes 3–6 months. Consideration of ankle support or taping, and possibly foot orthoses for the first year postoperative should be assessed. Most athletic patients use ankle brace or tape for the first sport season after the surgery.
20.3 Conclusion
Recurrent peroneal tendon subluxation is an uncom-mon sports- and road-related injury. It occurs when the acute injury is misdiagnosed or not adequately man-aged. The primary pathology is the damage of the Superior Peroneal Retinaculum, which is the main restraint to the peroneal tendons. Diagnosis relies on clinical suspicion and clinical examination. There is no standardized method to report the severity of the condition, and therefore, it is difficult to compare the various case series. Many surgical techniques have been described, but it is hard to understand from the relatively small series which procedure is the gold standard. In our experience, if an anatomic approach is used, reattachment of the SPR is a most appropriate technique. Rarely, the retinaculum in recurrent cases may not be robust enough to withstand repair, and a different approach to the problem may be required. Randomized controlled trials may be the way forward in determining the best surgical procedure for sublux-ing peroneals. Repair of torn Peroneal tendons appears
more straightforward with tubularization of the ten-dons involved. Tenodesis to the adjacent peroneal ten-don is needed in cases of excision of an Os Peroneum, and where >50% of the tendon girth is lost or more than 2 cm of tendon length is damaged. FHL trans-fer may be indicated in special cases where recon-struction is not possible. Surgeons should consider other forms of structural pathology such as ankle instability, exostoses, calcaneal varus, and plantar-flexed 1st metatarsal; these should be addressed appropriately as described in Chap. 37.
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